大气科学学报
大氣科學學報
대기과학학보
JOURNAL OF NANJING INSTITUTE OF METEOROLOGY
2011年
6期
763-768
,共6页
周宏伟%王群%夏文梅%仓粟
週宏偉%王群%夏文梅%倉粟
주굉위%왕군%하문매%창속
短时特大暴雨%龙卷%中尺度涡旋
短時特大暴雨%龍捲%中呎度渦鏇
단시특대폭우%룡권%중척도와선
short-term heavy rain%tornado%mesoscale vortex
利用地面加密自动站和多普勒天气雷达资料,对2006年7月3日发生在盐城的龙卷和短时强降水等强对流天气过程进行了详细分析。结果表明:此次强对流天气发生的天气背景是江淮梅雨期暴雨形势,即高空东移的西风槽、中低空西南急流以及强烈的对流不稳定。地面中尺度涡旋的发展、维持为强对流天气的产生提供了持续强劲的上升运动;龙卷发生在非超级单体风暴中低层反射率因子梯度区上,在平均径向速度图上出现了明显的小尺度涡旋特征。另外,西太平洋副热带高压和赤道辐合带上活动的3个热带系统为短时强降水提供了超常的充沛水汽,短时特大暴雨发生在中低空急流增强到最强并开始减弱的时段内,与大于50dBZ的强回波面积的变化关系密切。
利用地麵加密自動站和多普勒天氣雷達資料,對2006年7月3日髮生在鹽城的龍捲和短時彊降水等彊對流天氣過程進行瞭詳細分析。結果錶明:此次彊對流天氣髮生的天氣揹景是江淮梅雨期暴雨形勢,即高空東移的西風槽、中低空西南急流以及彊烈的對流不穩定。地麵中呎度渦鏇的髮展、維持為彊對流天氣的產生提供瞭持續彊勁的上升運動;龍捲髮生在非超級單體風暴中低層反射率因子梯度區上,在平均徑嚮速度圖上齣現瞭明顯的小呎度渦鏇特徵。另外,西太平洋副熱帶高壓和赤道輻閤帶上活動的3箇熱帶繫統為短時彊降水提供瞭超常的充沛水汽,短時特大暴雨髮生在中低空急流增彊到最彊併開始減弱的時段內,與大于50dBZ的彊迴波麵積的變化關繫密切。
이용지면가밀자동참화다보륵천기뢰체자료,대2006년7월3일발생재염성적룡권화단시강강수등강대류천기과정진행료상세분석。결과표명:차차강대류천기발생적천기배경시강회매우기폭우형세,즉고공동이적서풍조、중저공서남급류이급강렬적대류불은정。지면중척도와선적발전、유지위강대류천기적산생제공료지속강경적상승운동;룡권발생재비초급단체풍폭중저층반사솔인자제도구상,재평균경향속도도상출현료명현적소척도와선특정。령외,서태평양부열대고압화적도복합대상활동적3개열대계통위단시강강수제공료초상적충패수기,단시특대폭우발생재중저공급류증강도최강병개시감약적시단내,여대우50dBZ적강회파면적적변화관계밀절。
The tornado,short-term heavy precipitation and other convective weather in Yancheng City on 3 July 2006 are analyzed based on the data of dense surface automatic meteorological stations and Doppler weather radar.Results show that the weather background of the convective weather is Changjiang-Huaihe storm weather situation of the Meiyu,including the westerly trough eastward in upper levels,southwest jet stream in low-mid levels and strong convective instability.The development and maintenance of surface mesoscale vortex cause a continued strong upward motion for the convective weather.The tornado occurs in the large reflectivity gradient region in low-mid levels of the non-supercell storm,with a marked small scale vortex feature in the average radial velocity.In addition,three tropical systems in the western Pacific subtropical high and the ITCZ provide abundant moisture for the short-term heavy rainfall.There is a close relationship between the short-term heavy rainfall (occuring in a period of the increasing to the strongest,and to the beginning of decrease for the jet stream in low-mid levels) and the strong echo area larger than 50 dBZ.